错误中的错误遇到静态解析符号值。在 appmodule 中的角度答案

【问题标题】：ERROR in Error encountered resolving symbol values statically. in appmodule in angular错误中的错误遇到静态解析符号值。在 appmodule 中的角度
【发布时间】：2018-03-22 20:16:54
【问题描述】：

我正在尝试在应用程序启动之前以角度读取配置文件。我遇到了一个解决方案，但是当我第一次使用 commang ng serve 时，我一直收到错误消息。然后我重新保存代码，webpack 编译成功，没有错误。并且代码工作正常。错误是

ERROR in Error encountered resolving symbol values statically. Function calls are not supported. Consider replacing the function or lambda with a reference to an exported function (position 117:45 in the original .ts file), resolving symbol AppModule in C:/Repo/rvm-web-ui/AdaRvmWebClient/src/app/app.module.ts

我添加到 appmodule.ts 的行

 AppConfig,
    { provide: APP_INITIALIZER, useFactory: (config: AppConfig) => () => config.load(), deps: [AppConfig], multi: true },

还有appconfig文件

import { Inject, Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import { ConnectionHelper } from 'app/config/connections';

@Injectable()
export class AppConfig {

    private config: Object = null;
    private env:    Object = null;

    constructor(private http: Http) {

    }

    /**
     * Use to get the data found in the second file (config file)
     */
    public getConfig(key: any) {
        return this.config[key];
    }

    /**
     * Use to get the data found in the first file (env file)
     */
    public getEnv(key: any) {
        return this.env[key];
    }

    /**
     * This method:
     *   a) Loads "env.json" to get the current working environment (e.g.: 'production', 'development')
     *   b) Loads "config.[env].json" to get all env's variables (e.g.: 'config.development.json')
     */
    public load() {
        return new Promise((resolve, reject) => {
            this.http.get('conf/env.json').map( res => res.json() ).catch((error: any):any => {
                console.log('Configuration file "env.json" could not be read');
                resolve(true);
                return Observable.throw(error.json().error || 'Server error');
            }).subscribe( (envResponse:any) => {
                this.env = envResponse;
                let request:any = null;

                switch (envResponse.env) {
                    case 'production': {
                        request = this.http.get('conf/config.' + envResponse.env + '.json');
                    } break;

                    case 'development': {
                        request = this.http.get('conf/config.' + envResponse.env + '.json');
                    } break;

                    case 'default': {
                        console.error('Environment file is not set or invalid');
                        resolve(true);
                    } break;
                }

                if (request) {
                    request
                        .map( res => res.json() )
                        .catch((error: any) => {
                            console.error('Error reading ' + envResponse.env + ' configuration file');
                            resolve(error);
                            return Observable.throw(error.json().error || 'Server error');
                        })
                        .subscribe((responseData:any) => {
                            ConnectionHelper.SERVER_IP = responseData.server;
                            ConnectionHelper.SERVER_PORT = responseData.port;
                            ConnectionHelper.SERVER_URL = ConnectionHelper.SERVER_IP+":"+ConnectionHelper.SERVER_PORT+ConnectionHelper.ADA_URL;
                            resolve(true);
                        });
                } else {
                    console.error('Env config file "env.json" is not valid');
                    resolve(true);
                }
            });

        });
    }
}

【问题讨论】：

标签： angular dependency-injection provider

【解决方案1】：

看起来使用函数定义或 lamda 函数已被弃用。我需要从 app 模块中提取函数并在 AppConfig.ts 中定义它（您可以在任何文件中定义它）

export function initConfig(config: AppConfig){
    return () => config.load() 
   }

然后改了app模块

 AppConfig,
    { provide: APP_INITIALIZER, useFactory: initConfig, deps: [AppConfig], multi: true },

我希望这对某人有帮助

【讨论】：